For a long time, veterinary medicine considered cats to be small dogs. However, in the past couple of decades, studies have begun to show that cats are not just small dogs—especially in their nutritional requirements. Cats are strict carnivores that originated in the desert. In the wild, they eat rodents and small birds: self-contained, high-protein meals made up of about 75% water and very few (less than 5%) carbohydrates. Cats are designed to have all their nutritional requirements met with these package meals and consequently have a limited capacity for metabolizing carbohydrates and a relatively low thirst drive.

So what happens when we feed high-carbohydrate, low-moisture, plant-based food to these animals designed to have all their nutritional requirements met by a low-carb, high-moisture, animal-protein diet? Exactly what you might expect: chronic dehydration leading to kidney and bladder dysfunction—obesity from unused calories being packed into fat—increased risk of diabetes from excess fat and sugar lingering in the bloodstream—dry skin and poor hair coat from missing essential fatty acids found in fresh prey—the unknown health effects of chemicals and preservatives in the heavily-processed dry foods.

That’s the bad news. The good news is that things are changing—for the better. In 2005, we began recommending that all cats be fed only high-quality canned food, and since then, we have seen a dramatic decrease in the number of sick cats coming through our doors. The number of cats diagnosed with feline lower urinary tract disease (FLUTD) in our practice in the last seven years has dropped by 49.5%, and blocked cats, an emergency that we used to see at least monthly, has decreased to a few cases a year. Cats that have had a bout with cystitis (bladder inflammation) have a 90% chance of never relapsing if fed only canned food. With careful monitoring and a high-quality diet, almost all of our diabetic patients are eventually able to stop daily insulin injections. Most overweight cats lose weight simply from switching from dry to canned food, and the progression of diseases such as renal (kidney) failure and inflammatory bowel disease (IBD) is often slowed on canned food.

For more information, visit the Feline Nutrition Awareness Effort and Feeding Your Cat: Know the Basics of Feline Nutrition.